In general, space power applications require stringent performance characteristics for harsh environmental conditions including radiation hardening performance and high stability performance over extended periods, which should be independent of load drift and step changes due to environmental effects. In particular, there is a need for a current source that is capable of providing an accurate and stable current through high-bit resolution (e.g., 22-bit resolution) under a constant temperature environment (e.g., +/−0.1° C.).
Current conventional space power applications offer no known solution that provides a high level of performance under a changing load. Some conventional power applications use semiconductor devices in ways that directly affect the stability of current in these devices, which often forces radiation impacts of less than 10 ppm. Typically, the bandwidth of these devices does not meet system requirements, and in some instances, drift rates are at or near the allowable limits. With conventional power applications, there is no means of compensating for these deficiencies.
As a result, there exists a need to provide a stable current that meets requirements listed above under load drift and radiation conditions.